This patch adds microcode part of the firmware loader.

v4 - splits FW loader part into two smaller patches.
Acked-by: NBo Cui <bo.cui@intel.com>
Reviewed-by: NBruce W. Allan <bruce.w.allan@intel.com>
Signed-off-by: NKaren Xiang <karen.xiang@intel.com>
Signed-off-by: NPingchaox Yang <pingchaox.yang@intel.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>